Process of distilling turpentine from crude pine-gums of various ages.



UNITED STATES PATENT OFFICE.

BOBSON DUNWODY, ,OF KIRKWOOD, GEORGIA.

PROCESS OF DISTILLING TURPENTINE FROM CRUDE PINE-GUMS OF VARIOUS AGES.

No Drawing.

Specification of Letters Patent.

Application filed March 11, 1911.

Patented Mar. 4,1913.

Serial No. 613,934.

To all whom it may concern:

, Be it known that I, RonsoN- DUNWODY, a

.citizen of the United States, residing at This invention relates to processes of distilling turpentine from crude pine gums of various ages, and has for its object to produce a procedure which will get the turpentine out of the gums in a quicker, more etlicient, and more rational manner than the methods heretofore proposed. 1

It is now well known that in order to obtain a good quality of rosin it is necessary that it should not become charred or. carbonized, and in the distillation of crude pine gums, the free or uncombined water and lighter oils first come over very readily, beginning to distil off at about, say, 212 F. Then as the temperature is raised, the volatile oils will come oil until the temperature of say,-about 275 F. is'reached, when the water which is intimately mingled, and possibly chemically combined with the rosin, will be distilled off. It now, the heat is not checked as by the addition of water to the still, the temperature will rise very rapidly until it reaches say, 316 F., when carbonization will begin, and thereby so discolor the rosin as to render the product of a much lower grade than would otherwise be the case. It is further well known that in dealing with crude pine gums in general, if water is added to the still at abi'iut 260 F., and the temperature is permitted to same way I have found that the tempera ture during distillation at which the gum which was collected during the third year of scarification Wlll give up its entrained other words, I have found that if the first,

second and third year, as well as other gums, are all treated alike, and on the supposition that they all give up the water inherent in them at about the same temperature, a great deal of time is unnecessarily lost during distillation, and therefore, the process of obtaining turpentine may be very materially cheapened if the procedure now to be disclosed is followed.

Accordingly, my invention consists in the novel steps and combinations of steps for treating first, second, third, and later year gums in the process of distilling otf their contained turpentine, all of which will be more fully hereinafter disclosed, and particularly pointed outin the claim. That is to say, I have observed that .virgin gum dipped in March, April and May will part with substantially all of its inherent water during distillation at or about 230 F., so that water should be added to the still in order to keep the temperature from rising too suddenly in dealing with said gum when about 230 F. has been reached. On the other hand, if this first year virgin gum has been dipped from June to July, it will not pm with its inherent water until about 2et0 F. has been reached, and therefore, water should be added to the still when dealing with said last mentioned gum when this latter temperature has been reached. Further, I have discovered that if this first year virgin gum has been dipped after July it will part with its water at or about 250 F., and consequently, water should be admitted to the still to prevent an undue rise of temperature in dealing with this last mentioned gum when the thermometer shows a temperature of about 250 F. ()n the other hand, if what it known as yearling gum, or

will be substantially all gone when a ternperature of about 260 F. has been reached in the still. On the other hand, if this gum has beencollccted after the month of May, the temperature at which it loses its entrained water will gradually rise until about 27 has been reached in the still. --Therefore, when dealing with this yearling'gum, if an undue rise ,of temperature and consequen't carbonization is not to take place, one

should addw'ater at260 F. for those collectime of. gum made in March, April and May and-should add the water at gradually in-.

creasing temperature up to say 270 F., when the collections have been made" after May. The'gum collected during-the-lthird .years scarification of a tree is called buck- ,gum, and I have found that when this buck gum is collected during March, April and May it will have lostsubstantially all of its contained water when about, 265. F. has

, been reached,-and if it was collected later in the year, the point at which it'haslost all of its water in the still will be about 27 5 F; ,It consequently follows that in dealing with back gum, water should be added at term peratures of about 260 Ff-to .275 F., according tothe time of: yearat-which it was collected. There 'is still a fourth" class of" gum known as scrape which is the gum that adheres to the tree after the more fluid gum. has descended into the collecting boxes, and which has therefore; had more or less of its 1 volatile spirits taken. from it by the action of the sun and weather. Itis in a solidified condition, is often an inch or more in thickness and occurs'in the first, second and third year of scarification, as well as in "fact,-the

vlater years of scarification. This scrape is mechanically removed, from the-tree at the end of.the season, but in removin it a considerable quantity of chips or woo ymaterial comes 01f withlthe resin, and upon'examination, this wood isfound to'bethoroughly'im;

pregna'ted with the re'sinous materials, and to be of a light red color. Upon distilling scrape containing its woody'constituents it is found, that unless special precautions are. taken, the coloring matter of the wood will color the rosin and thereby make it of lower comnierical value than would otherwise be the case. It 'is-also found howevep-that the contained wood will not 'stainthe rosin an objectionable-extent if the. temperature iskept below say 275 F. probably owing to the fact that the acids or other staining;

matter in the wood are not liberated muc below that. temperature. It is therefore ob vious that if thesewoody constituents canbe'i removed from the rosin at or ;below-'275 F.,* the value and grade of the product can be increased. As a matter of fact, in-carrying out the process of distillation ofscrape the wood is mechanically removed by means of scoop strainers or their equivalent, and since I have found that the said scrape ispractically deprived of its inherent water when a temperature of 275 F. is reached, in carrying'out my process I cause the said woody 7 material to be removed; then I begin to add water to the said scrape. By removing the wo0dy material atL this point, rather than at some-other-point'of temperature, the following advantages accrue :In order to re-- move the woody material it isnecessary to uncap the still, and if violent ebullition is taking place'in the still while it is uncapped,

a-greater or less quantity of spirits will be present in the vapors driven'froin the still,

and will therefore'be .lost. On the other hand, when the scrape has lost its water,

ebullition has practically ceased, and there fore a minimum loss of volatile spirits is incurred if the'uncapping takes place at about 275 F. In order tomake clear the special advantages of distinguishing, (dur-' ing the distillation operation,) between the difierent ages of the gum being distilled, it is only necessary to point out that according to the present procedure, it is known that all these gums can be successfully distilled if water is added in the neighborhood of say 260 F. It so happens that this temperature is a rough, mean temperature for the giving that a point is soon reached" at which, if one drives olfam'ore water, ebullition will cease and. the temperature will rapidly rise if water is not added and will quickly passthe 316 F. point where carbonization' starts, it

will be seen atonce that some intelligent idea ojfq'ust what is taking place in the gum is necessary if distillation isito be successfully accomplished in theshortest possible time. For examplHupp'ose one is working with first "yearjor virgin gum, and ebulliti'o-n' has practically stopped soon after 230 F. is

be very hardin'deed tocheck, so that if one waits until 260 F. is-reached before adding water, he will run considerable risk of the gum, or at least some portions of the same,- rising to a much higher temperature, and of having some discoloration take place. All

-reached, the rapidly rising temperature will I of this would, of course, be at once avoided if he'added the waterat 230 Again,-j gsuppose o n'eris worln'ng with third year buck a gumgaandadds water to the still at 260 F.,

during the latter part of the season-when the gumwould normally give up its iwa ter at about 270 F. then unnecessar water Wlll cook this water out of theistill than would have been the caseif the distiller had waited reached and. had added: water at that point.

izo

have been ad ed-and it will'ta e, longer to -'until say 270 or 275 F. had been Although. in practice some charges of gum will not incur asgreat a loss at times as will others, yet, especially iif one is working on October gum, there will always'be charges in the still in which the unnecessary loss of time will be considerable. In some cases this loss will amount to as much as two hours on 5 each charge, or say six hours a day; It therefore follows that although thepresent method of adding water to all ums indiscriminately at a temperature 0 260. F. is successful in practice, yet at the same time by carrying on the distilling operation in the light of the above disclosures a much o more intelligent operation is had, and a much more certain and better grade of products is at all times produced. a

It sometimes happens that a charg'iii the still consists of the first year, second year, and third year gum, and even sometimes scrape is mixed-in with the charge. Or it also happens that first yearand scrape, or

second year and scrape, or third year and scrape are mixed in the charge. In all of .these cases with the knowledge that the first year gum gives u its water at about 230 to 240 F.,' that t e second year gum gives up its water at about 260 to 270 F., and that the third year gum and scrape give up their water at about 275 F., the operator ma act with intelli ence and add the water at ust that point w ich will insure against carbonization, and will at the same time produce clear, unstained commercial products in the minimunrof time.

Although those accustomed to the distillation of turpentine will be able to practise 10 say 500 gallons or about 4600 pounds of this in the still, which was gathered in uly or August. A ood fire is built under the kettlera fire sue as six ticks of ordinary four foot cord woodrodu'ces-and 4 5 it is allowed to burn for aboutten minutes or until a temperature. of 212 is reached in the still. -The fire is now so regulated or maintained (the operator keeping his e e on the thermometer in the still) that't e temperature increases say about one degree perminute. About ten sticks of cord wood ke t in thefurnaceand added'one at a time .wi generally for the charge above cause thetem erature to rise at the desired rate. When t e tem erature has thus. risen to about- 240 in t e still, a continuous stream of water should be introduced, and of a size .to deliver about one gallon per minute. After the water enters, the fire is so regulated as to cause the temperature to rise about one degree per minute for fifteen minutes or until say 255for 260 is reached.

The firing after that is so regulated" as'to .the operator knows the character of his gun'r cause the temperature to rise about three tenths (.3) of a,degree per minute for say thirty minutes,,or until 265 or 270 has been reached. The next five degrees increase of temperature should be at the rate of about one tenth (.1) of a degree per minute, or

in other words, it should take about 50 minutes for the tern erature .to rise from say 265 to 270 or rom 270 to 275, as the case may be. The temperature is next heldbetween-say 270 and 280 until the spirits show on the testing glass one-quarter of an inch or 5 per cent. distillation. This will require about 20 minutes more before the desirable proportion of spirits coming over has been reached. The temperature is next increased at the rate of about two degrees per minute for 10 or 15- minutes; then the water is cut oil, the fire removed from under the kettle, and the charge turned out. Of course when the gum is gathered at a. different time of year, or when it is a other than the virgln, or when there is a dlfierent amount of gum in the still, the above data would somewhat changed, but t ose skilled in this art will have no difiicultg with the aid of the above disclosure,-in makingthe necessary allowances. For example, as is at present. well'known, the amount of water would vary for virgin gum no matter what fame of the year it is gathered, but the same rate of increasing temperature and the same rate of addin water could be maintained no matter w at amount of gum is in the kettle, while the time element of adding the water and the time element of maintaining the temperature would vary in proportion to they 0 amount of gum. That is to say, if, for example, 10 barrels of gum is-belng treated, as above described, the total time 'taken' would be-two hours and thirty minutes. 5

barrels of gum on the otherulliiy'd, take only about one hour and fifteen utes In practice of course suitable'and now .well

known thermometers are placed i n tl i e still, and the temperature of the inter or thereof is carefully and constantly noted, sothat if he can add water at the right time to produce the most eflic1ent.resu1ts.-

What I claim is Y The process. of distillin turpentine and recovering thehighest gra e rosin from virgin'res-inous'gum, whichconsists in gradually adding water to said gum when said temperature has risen substantially to 240 0 F., substantially as described.

'In testimony whereof, afix my signature, in presence of two witnesses.

ROBSON D mwoDY.

Witnesses: f

T. A. Wu,

R. M. P 

